Technical Field
The present invention relates to a three-dimensional precise intracavitary radiotherapy method for treating tumours, and in particular, to a three-dimensional precise intracavitary radiotherapy method for treating tumours, and relates to a three-dimensional precise intracavitary radiotherapy system for treating tumours, and further relates to a fabrication method of an intraluminal radiation stent.
Related Art
With the development of endoscopy and interventional radiology, a minimally invasive ERCP or PTCD method is utilized for cholangiocarcinoma treatment, where external drainage is changed to internal drainage, operations are simple, and survival quality is better than that of a bypass surgery. In 1985, Carrasco fabricated a first extensible metallic bile duct stent, and a better treatment effect is achieved. Similar treatment activities are also gradually carried out since 1990s in China. In a metallic stent bile duct drainage operation, an operation wound is small, a stent with a larger diameter can be implanted by using a thinner catheter, early complications are fewer, and an operative mortality is lower. After a metallic internal stent is implanted into a narrow bile duct, the metallic internal stent can self-expand to an original diameter, and exert a continuous expansion force on a narrow lumen wall, ensuring stability of the stent. There are some limitations to application of a current bile duct stent. For example, the current stent can be used for only palliative treatment, and a long-term curative effect for cholangiocarcinoma has been unoptimistic. Therefore, if a targeted local radiotherapy can be combined with stent expansion, toxic and side effects of total body radiation can be reduced, and better treatment effects can be achieved.
To combine expansion of a bile duct and a targeted local radiotherapy, in Chinese Patent Application No. CN101695458A, a bile duct radiation stent is disclosed. A specific structure of the bile duct radiation stent is shown in FIG. 1 to FIG. 5, and includes an external stent 1 and an internal stent 2. The external stent 1 and the internal stent 2 are in a separate state when they are not used, and only when they are used, a main body of the internal stent 2 expends in the external stent 1. As shown in FIG. 3, the main body of the internal stent 2 is a cylindrical skeletal mesh structure 7 woven by nickel-titanium wires. As shown in FIG. 1 and FIG. 2, a main body of the external stent 1 is also a skeletal mesh structure 3 woven by nickel-titanium wires. Radioactive particle filling capsules 4 are mounted on a surface of the skeletal mesh structure 3. The particle filling capsules 4 may be fixed by using barbs (relative to a placing direction) on the surface of the skeletal mesh structure 3, or may be fixed by suturing. Radioactive particle filling capsules 4 may use a small-packet structure 5 with an opening as shown in FIG. 4. The small-packet structure 5 is made of an artificial vascular membrane tube or a polymer tube. An upper portion of the small packet 5 is provided with a small opening to allow a radioactive particle to be placed into and prevent the radioactive particle from exiting. The small pockets 5 are continuously linearly distributed on the surface of the skeletal mesh structure 3, and are axially distributed. Each line of linearly arranged small pockets 5 may be uniformly distributed on the circumferential surface of the skeletal mesh structure 3, or may not be uniformly distributed. The radioactive particle filling capsules 4 may also use a structure shown in FIG. 5. The radioactive particle filling capsules 4 are tubular structures made of plastic heat shrink tubes, and have three-dimensional positioning marks, and a tube diameter at a position at which a radioactive particle is placed is greater than a tube diameter at a position at which a radioactive particle is not placed.
However, the foregoing stenting internal radiotherapy in the prior art is not precise, positions, a dose, and a radioactive source type of radioactive particles are coarsely selected and arbitrarily placed on a stent according to experience of a doctor, rather than determined by a range, a position, and a size of a specific lesion, a viability and a type of tumor cells, and the like. Moreover, for such a placing manner, it is also not considered how to avoid normal tissue in a treated area and protect the normal tissue from radiation of a radiation dose. Consequently, a lesion area is usually not radiated by an appropriate radiation dose, and normal tissue is unnecessarily damaged by radiation. A more precise and efficient stenting intraluminal radiation therapy method and equipment are urgently needed clinically, to overcome the shortcomings in the prior art.